The present invention generally relates to medicine, in particular to orthopedic medicine and traumatology, and more specifically to a system provided for lengthening of limbs by generating a dosed, non-traumatic distraction osteogenesis, with the pace of correction depending on a magnitude of distraction forces.
The amount of distraction force applied, the distraction rate, soft tissue tension, microcirculation conditions, and osteogenesis activity are all important factors in limb lengthening procedures. A critical factor to osteogenesis activity is knowledge of the force values of distraction, which allows one to timely diagnose conditions, such as, incomplete corticotomy, premature consolidation, and osteogenesis failure.
Another critical factor to osteogenesis activity is the distraction frequency. It has been shown that an increase in the distraction rhythm, e.g. (1 mm in 4-6-8 increments), ensures more favorable conditions for the formation of distraction regenerate. In addition, lengthening in an automatic microdistraction mode, e.g. (1 mm in 60 to 1840 increments), possesses a number of essential advantages. First, less tension developed in soft tissue provides more adequate microcirculation and enhanced metabolic processes in the area of bone regenerate, resulting in more active bone formation. Second, in the neuromuscular system, nerve and vessel trunks are less damaged, reducing the number of contractures in adjacent joints along with other complications. Under these conditions, the limb lengthening process more closely resembles natural physiological growth.
A challenging problem today involves measuring the tension status of the “device-patient” system during functional weight-bearing trials, which makes it possible to determine the stiffness of regenerate being formed at any period of time. What is needed is a system that can determine the stiffness of regenerate and select the optimized rhythm of lengthening. The present invention discloses an apparatus that determines bone regenerate stiffness in a corticotomy zone using external elements and that automatically adjusts the rate of lengthening to correspond to the most favorable rhythm of the patient.